1. Technical Field
This patent disclosure relates to data processing, and in particular to a managed recovery service that supports orderly recovery of logical domains.
2. Background Information
Virtualization is an approach to data processing that allows multiple operating systems and applications to share the hardware resources of a single host computer. Ideally, virtualization provides resource isolation so that each operating system does not realize that is sharing resources with other operating systems and further such that it cannot adversely affect the execution of the other operating systems. Virtualization is generally recognized as enabling servers, co-located hosting facilities, distributed web services, secure computing platforms and other applications to efficiently use the underlying physical resources.
A virtual machine is a software representation of a data processing machine such as a computer that executes programs in the same manner as a corresponding physical machine. Multiple virtual machines each running their own operating system (called the guest operating system) a frequently used in server consolidation, where different services that in the past had to run on individual physical machines can now instead run in separate VMs on the same physical machine. It is even possible that the guest operating systems do not need to be compliant with the hardware making it possible to run different operating systems on the same physical machine.
In a one common implementation of a virtual environment, a hypervisor is a piece of software, firmware and/or hardware that acts as a virtual machine manager to create and runs different the virtual machines on a given physical host machine. It is also common to use the term logical domain (LDOM) to reference a full virtual machine that runs an independent operating system instance and its virtualized CPU, memory, storage, console, networking, and other resources. These paradigms allow logical grouping of system resources into multiple, discrete systems, each with their own operating system, resources and identity but all within a single physical computer system. For example, a variety of application software can be run simultaneously in different logical domains, all while keeping them independent of performance and security concerns. The use of logical domains can help achieve greater resource usage, and better security.
One of the logical domains, a so-called control domain, is typically run under, or as an integral part of, the hypervisor. The control domain is responsible for creating and manages all other logical domain configurations within a server platform. For example an important task of the control domain is to manage and map the other logical domains serving as guest systems that run the applications.
Virtual data processing resources are now widely available through various data processing providers. Most data processing environments, including virtualized environments, must also tolerate faults of one kind or another. As a result, managed disaster recovery is an increasingly requested offering from the customers of both private and public cloud services. Because the customers of these services typically do not have the expertise to master the technical complexities and compromises of disaster recovery (e.g., minimizing downtime while controlling costs) they look to the service providers for reliable managed recovery options. Managed recovery services can avoid the need for a data center operator to go about rebuilding and restoring their virtual environments on their own.